"When I first met him [Zappa] in New York, the art studio was in his apartment — but that was only for a brief period. I didn't actually live there [as widely reported], but I would commute to work at his place. When we moved to LA . . . he had rented the log cabin, I had a wing of it. It was my living quarters and art studio, which I rented separately from them."[1]

For over a decade, Schenkel, working in either an annex of the Zappa household or in his own studio, attempted to give visual form to Zappa's music while developing his own, distinctive style.

"I love naive and folk art, art that has an unfinished look. I don’t like the polished for the most part. Now what that means or where it comes from I'm not sure. But I was probably influenced graphically by artists I saw in school. And of course there's the comic book look — like Krazy Kat. A part of it was just lack of skill, trying to take advantage of my own naivety. I'd really only had a semester of art school, so I hadn't evolved my style when I was doing all of this. It just comes natural, too."[1]

Schenkel began work for albums on Straight Records, a label owned by Zappa and manager Herb Cohen. These covers were for artists such as Lenny Bruce, Tom Waits, Tim Buckley and Captain Beefheart. For Trout Mask Replica Schenkel went to a local fish market to buy the carp head that he wanted to use on the album cover. He hollowed out the head leaving just the face, like a carnival mask. Beefheart instinctively picked it up and held it to his face and sat for over two hours while Schenkel took photographs. Inside the mask the smell was choking and intense but the Captain was good-natured about the whole process. At one point Beefheart picked up a saxophone and started to play something "raw" through the mouth of the stinking fish. Schenkel has film of the carp playing sax.[3] The artwork for Zappa's Burnt Weeny Sandwich was originally intended for an Eric Dolphy album.

Schenkel provided vocal for Zappa's album Lumpy Gravy. He was production designer for the film 200 Motels and can be seen in the Zappa movies Uncle Meat and Video From Hell. The inspiration and title for the track "For Calvin (And His Next Two Hitch-Hikers)" (from The Grand Wazoo) was from an incident as related by Schenkel to Zappa. When Zappa came to register his son Dweezil's name, the hospital refused the unusual name. Zappa instead used a list of friend's names that came to mind: Ian Donald Calvin (after Schenkel) Euclid.

By the mid-1970s Zappa's output had slowed while he was in dispute with Cohen and Warner Bros. Records and so Schenkel returned to Willow Grove hoping to jump-start an art career separate from Zappa and the record industry. There he began his own "mail order" art business. In the 1980s Schenkel resumed occasional work on Zappa projects.

In 2012 Schenkel appeared on the television program History Detectives. He was asked to comment on a collage, made in the early 1960s, which the program host determined to be an authentic early piece of artwork by the young Zappa.